Alitalia A321 brakes failure @ Naples

[sidestick driver]

A340/A330 uses blue system for parking brake????? Can be used with out anti-skid and with antiskid (FCOM 3.04.32 ref), and finally parking brake can used in short bursts, set-off-set-off.FCOM 3.02.32 A343/A345
A330 landing gear

From a quick training guide

Braking system
•Carbon disc brakes are standard.
•Normal system (Green hydraulic system supply) :-electrically signalledthrough antiskid valves
-individual wheel antiskid control-autobrake function
- automatic switchover to alternate system in event of Green hydraulic supply failure.
•Alternate braking system with antiskid (Blue hydraulic system supply) :
-electrically signalledthrough alternate servovalves-hydraulically controlled through dual valve
-individual wheel antiskid control-no autobrake function.
•Alternate braking system without anti-skid (Blue hydraulic system supply or Blue brake power
accumulator) :-hydraulically controlled by pedals through dual valve
-brake pressure has to be limited by the pilot referring to the gauges.
-no autobrake function-no antiskid system
•Parking brake (Blue hydraulic system supply or Blue brake power accumulator :
-electricallysignalled-hydraulically controlled with brake pressure indication
on gauges.
•The Braking and Steering Control Unit (BSCU)is digital dual-channel double system (control and monitoring)
computer controlling the following functions :-normal braking system control
-anti-skid control (normal and alternate)-autobrake function with LO, MED, MAX.
-nosewheel steering command processing-brake temperature signal processing
-monitoring of all these functions.
A330 landing gear
Antiskid system
•From touchdown, aircraft speed is computed based on touchdown speed (wheels) and integrated deceleration
(ADIRS). This reference speed is compared with each wheel speed to generate a release order for closing
the normal servovalve in case of skid exceeding 16%.
•Brake pedal orders open this servovalve which is also modulated by anti-skid closing signals.
Autobrake system
•From touchdown, a specific speed is computed based on touchdown speed (wheels) and programmed
deceleration (low, medium, max). This programmed speed is compared with each wheel speed to generate
a release order for closing the normal servovalve to meet selected deceleration.
•If the reference speed exceeds programmed speed (contaminated or iced runways), the former will take
over for the antiskid to modulate the normal servovalveBraking principle